Pocket telegraph receptor



March 24, 1931. P. J. RUDDY POCKET TELEGRAPH RECEPTOR Filed Oct. 3, 19272 Sheets-Sheet l TIC-h z TIGii- I N VEN TOR flint]; Jjizwloj j,

ATTORNE'Y.

P. J. RUDDY 1,797,696

POCKET TELEGRAPH RECEPTOR Filed Oct. 35, 1927 2 Sheets-Sheet 2 flfiigiT16: J

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. V I ATTORNEY.

Patented Mar. 24, 1931 UNITED STATES PATRICK J. BUDDY, F CENTRALIA,PENNSYLVANIA POCKET TELEGRAPH RECEPTOR Application filed October 3,1927. Serial No. 223,594.

1 My invention relates to wireless receivers, and has for its principalobject to provide a receptor which requires, neither ground nor aerialand which is adapted to pick up signals Withdistin'ctness and accuracy.r

Another object of my invention is to provide a small, compact receptorwhich may be readily carried in a pocket.

Still another object of my invention is to provide an instrument of thecharacter mentioned equipped with simple means for tuning to differentfrequencies and of such construction as to provide a simple adjiistmentfor regulating the tone and volume.

The invention comprises a pair of cores for induction coils, one ofwhich is adjustable toward the other and betweenwhich a contact is madeby means of a contactor yieldably supported therebetween, the adjustablecore being adapted to exert varying pressure on the contactor in thetuning of the instrument.

In the drawings Figure 1 is a side view of a pocket receptor embodyingmy invention, and

Figure 2 a central vertical sectional'view therethrough, certain partsbeing broken away.

Figure 3 is a transverse sectional view, taken on line 3-3 on Figure 1,

Figure 4 a transverse sectional view taken on line4-4 on Figure 1, and

Figure 5 a wiring diagram. The invention consists primarily of twoinduction coils of unequal strength, each of which has a magnetic core,a contactor floating between the ends of the two cores, and a phone orother receiver connected between the secondaries of the induction coils.

v The embodiment shown in the drawings has a casing 10, preferably madeof insulating material and closed by a cap 11 carrying binding posts 12and 12 to which wires from a battery or other source of energy may beattached. A tube 13 is closed at its lower end by a plug 14 and at itstop by a bushing 15 which abut cap 11 and the top of casing 10,respectively, and hold the tube against longitudinal movement. Theseparts should be made of insulating material and tube 13 should be madeof material which will allow free passage of magnetic flux.

The receptor shown in the drawings is designed to be held in anapproximately upright position and the stronger induction coil is placedin the upper part of casing 10. The

lower and weaker coil has a core 16 of magnetic material centrallydisposed in the lower part of tube 13 and provided at its upper end witha head 17 on which a metallic contactor 18 is floated in a conductingliquid. Head'17 should fit snugly or be sealed in tube 13 so thattheliquid may not leak past. Contactor 18 is preferably spherical inform and has been shown asla solid ball floating in a bed of mercury 19but it is believed that variations may be made in this arrangement.

I use a steel ball. as the contactor, but the requirement is believed tobe that it be of some element which, in contact with mercury, will allowelectricity to flow in one direction but not in the other, or to allowit to flow more readily in one direction than in the other.

The head 20 of a plunger 21, forming the core of the upper coil, isdisposed immediately above contactor 18 and adapted to be brought intoand out of contact therewith by means of a knob 22 threaded into plunger21 and eX- tending throughbushing 15 and the upper-8 end of casing 10.Head 20 should be in contact with contactor 18 at all times and the toneand volume of the instrument is regulated by the pressure, exerted bymercury 19, of contactor 18 against head 20. The pressure is primarilyadjusted by moving plunger 21 inwardly or outwardly; and thereafter amore delicate adjustment is effected by tilting the instrument more orless fromthe vertical to obtain the best relation between the contactor18 and the head 20. However, the instrument should not be tiltedsufliciently to bring lulhe dmercury into contact with the plunger Anear phone 25 is connected between the 9 secondaries of the inductioncoils and secured to casing 10 in any suitable manner, as by means oflugs 26 secured to the back of the ear phone and bolted to casing 10,and may be of the usual construction which consists, .1

in insulators at and 35 conforming in-outline to the interior of casing10 and encircling the top andcenter," respectively oftube '13 andholding same againsttransverse movement;

The secondary 36 of the upper induction *coil is formed by "winding theoutside of the upper part'of tube 13 with-a wire having one endconnected 'toone of'the'terminals of phone 25 and the turns near itsother end engaged by a slidingcontact .37'mounted on bar The secondary38ofthe lower induction coil is formedibywin'ding the'lower part of tube13 with .a Wire having one end connected to the other terminal of phone25 and the turns near its other endtengagedby a sliding contact 39mounted on a bar 40 having one end secured inanotchin insulat0r35'andits lower end in a notch formed in an insulator ll encircling thelower'en d of tube 13 and conforming in outline to the interior ofcasing'10.

A slot 42 extends longitudinallyof casing 10 in alignment with bars 33and lO so that contacts 37 and 39 may beslid along the bars by means ofbuttons 43 and 44 extending through the slot and securedto contacts 37and 39, respectively.

One end of bar 40'is electrically connected to binding post 12 so that,if the binding posts are connected to a suitable source of energyasindicated bybattery 45 in Figure 5, current may flow from binding post12 through primary 31, head 1?, mercury 19, contactor 18, head 20,primary .32, bar 33, contact 37, secondary 36, phone 25,'second-ary 38,contact 39, bar &0 and binding post 12f back 'tobattery 45.

The Wire composing secondary 36 may be wound in the same direction asthe wire composing'secondary 38 but I find that the instrument is moresensitive andfunctions more efliciently if these two coils are woundinopposite directions. By winding primary 31 around core 16 and primary32 around plungor 21, electromagnets are formed which tend towork-against one another. Primary 32 should have more turns than primary31 and'the ratio'may be varied considerably but I find excellent resultsare obtained when primary 32 isprovided with three timesasmany turnsasprimary 31. The ratio between the primary and secondary of eachinduction coil may vary considerably also. For a receptor as shown inthe drawings, I find that a ratio of 1 8 is ample for ordinaryreception. Secondary coils 36 and 38 are wound opposite to one anotherand preferably have turns in the same proportion as primaries 31 and 32so that plunger 21 formsthe core-of a Considerably stronger magnet thandoes core 16. The

coils therefore function as electromagnets and induction coils and, as"their windings are electrically connected to one another, the entire length of wire is adapted to absorb electrical impulsesand'toserve as anaerial.

My invention is primarily designed for receiving wireless telegraphysignals and, when used for this purpose,'the windings of the severalcoils should be of sufficient length to bring the range of the receptorwithin'the band used in wireless telegraphy. The'tuning ofthe instrumentis aecomplishedby sliding'contacts 37 and 39 on bars 33 and 40 so as tocut in or cut out sufficient-turns of the secondary coils to tune theinstrument to the wave length desired.

In using the device, knob 22 is moved until head 20 comes substantiallyinto contact with contactor 18 and adjusted until a signal may be heardinthe ear phone. After the signal is heard, the pressure on contactor'18 is regulated until signal strength is obtained. Then, afineadjustment to regulate the. tone and volume of the signal is obtained byslightly tilting thedevice to get the proper relation between the member20 and the floating contact 18.

The impulses created by the s1gnals being received augments the magneticeffect of the coils of the member 18,

'rausing a 'slightbutdistinct vibratory m0Vemay be carried in a separatecase and connected to the instrument by means of'binding posts 12 and 12or they may be incorporated directly into the device and carried incasing 10.

The principles involved in this invention are new and I therefore do notwish to'limit myself to the application of the invention described orthe embodiment shown but consider that I am at liberty to incorporate myinvention into such structures as fairly come Within the scope of theappended claims.

Having thus described my invention, what I claim as newand desire to'secure'by Letters Patent'1s:

1. An instrument of the character scribed including upper and lowerinduction coils having magnetic cores, a bed of mercury on the lowercore, a contactor floating in the mercury and engaging the upper core, atelephone connected in series with the coils and means for regulatingthe pressure between the contactor and the upper core.

2. An instrument of the character de scribed including upper and lowerinduction coils having magnetic cores, a bed of mercury on the lowercore, a contactor floating in the mercury and having contact with theupper core; the upper coil being considerably stronger than the lowercoil and a telephone in series with the coils.

3. An instrument of the character described including upper and lowerinduction coils each consisting of primary and secondary windings andhaving magneticcOres, a bed of mercury on the lower core, a contactorfloating in the mercury and engaging the upper core, means forregulating the pressure between the contactor and the upper core, tuningbrushes connected tothe primaries and slidably engaging the secondariesof the coils, and a telephone connected between and in series with thesecondaries of the coils.

4-. An instrument of the character described including a tube, a core inone end of the tube, a primary winding on the core, a secondary windingon the tube over the primary, a plunger in the tube, a primary windingon the plunger, a secondary winding on the tube over the plunger, a bedof mercury between the core and plunger and in electric contact with theformer, a contactor floating in the mercury and having contact with theplunger, and a telephone connected between and in series with thesecondary windings.

5. In a device of the class described a pair of induction coils eachconsisting of a primary and a secondary winding, a floating contactor inpermanent connection with the end of the primary of one of said coils, aterminal member for the end of the primary of'the other coil and inadjustable contact with said. floating contactor, and the device beingadapted to be manually supported when in use and tiltable to vary thepressure of the floating contactor on the adjacent terminalsubstantially as described.

6. A device as set forth in claim 5, in which the coils are in axialalinement and are wound in opposite directions.

7. In a device of the class described a casing adapted to be manuallysupported and by tilting said casing substantially as described.

8. A device as set forth in claim 7 in which the coils are in an axialalinement and are wound in opposite directions, substantially asdescribed.

9. A pocket radio receptor comprising a casing adapted to be manuallysupported, a pair of induction coils in said casing and each having acore a bed of conducting liquid electrically connected with one of thecores, a contactor floatingv in said liquid and engaging an end of theother core, the pressure of the floating contactor on said core beingvaried by tilting the device, a. tuning slide associated with said coilsand a phone in series with the coils, substantially as described.

In testimony whereofI have signed my name to this specification.

, PATRICK J. BUDDY.

containing a pair of induction coils of lesser and greater inductivity,respectively, a floating contactor in permanent connection with the endof the primary of the coil of lesser inductivity, a terminal member forthe end of the primary of the coil of greater inductivity, and means foradjusting said terminal to vary the contact with the floating contactor,and said contact being further regulated

